1. Technical Field
This invention relates in general to optical networks and, more particularly, to optical ingress router.
2. Description of the Related Art
Data traffic over networks, particularly the Internet, has increased dramatically recently, and will continue as the user increase and new services requiring more bandwidth are introduced. The increase in Internet traffic requires a network with high capacity routers capable of routing data packets of variable length. One option is the use of optical networks.
The emergence of dense-wavelength division multiplexing (DWDM) technology has improved the bandwidth problem by increasing the capacity of an optical fiber. However, the increased capacity creates a serious mismatch with current electronic switching technologies that are capable of switching data rates up to a few hundred gigabits per second, as opposed more than one terabit per second potential capability of a single DWDM fiber (a fiber optical cable contains twenty-four fibers). While emerging IP routers may be used to switch data using the individual channels within a fiber, typically at a few terabits per second, this approach implies that tens or hundreds of switch interfaces must be used to terminate a single DWDM fiber with a large number of channels. This could lead to a significant loss of statistical multiplexing efficiency when the parallel channels are used simply as a collection of independent links, rather than as a shared resource.
Different approaches advocating the use of optical technology in place of electronics in switching systems have been proposed; however, the limitations of optical component technology has largely limited optical switching to facility management/control applications. One approach, called optical burst-switched networking, attempts to make the best use of optical and electronic switching technology. The electronics provides dynamic control of system resources by assigning individual user data bursts to channels of a DWDM fiber, while optical technology is used to switch the user data channels entirely in the optical domain.
One important part of an optical network is the edge routers and, in particular, the ingress edge routers. The function of an ingress edge router include routing the IP packets, assembling IP packets into data bursts according to the addresses of their destination egress edge routers and other information (e.g. packet classes for quality of service purposes), generating burst header packets and scheduling the data bursts and control information for their transmission on output optical channels. The goal is to carry out all these functions efficiently. The main technical problem in the design of edge routers is how to feed the high-speed optical pipes efficiently, which is critical to the overall efficiency of an optical burst switched network.
Therefore, a need has arisen for a method and apparatus for providing an efficient ingress routers for an optical burst-switched network.